Organic light emitting display device

ABSTRACT

An organic light emitting display device having an electrostatic capacitive type touch panel function. In one embodiment, the organic light emitting display device includes a substrate, a display unit on the substrate, an encapsulation substrate having a side facing the substrate, a touch unit facing the display unit and including a plurality of first sensors electrically coupled with each other and extending in parallel rows along a first direction, and a plurality of second sensors electrically coupled with each other and extending in parallel columns along a second direction crossing the first direction, and an insulation layer on at least a portion of the first sensors and second sensors.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/080,179, filed on Jul. 11, 2008, the entire content of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device having an electrostatic capacitive type touch panel.

2. Description of the Related Art

Recently, the use of portable thin flat display devices has increased considerably. A representative example of a flat display devices is an electroluminescent display device, which is an active matrix type display device expected to become the next generation display device due to its wide viewing angle, high contrast, and fast response speed. Also, compared to an inorganic light emitting display device, an organic light emitting display device having an emissive layer formed of an organic material has better luminance, driving voltage, and response speed, and is capable of realizing multi-colors.

In order to allow a user to input a command via a finger or a pen-type pointer, many studies have been conducted to obtain an organic light emitting display device having a touch panel function, such as an internal electrostatic capacitive type touch panel display device.

However, in the case of an organic light emitting display device having a internal electrostatic capacitive type touch panel, the thickness of the touch panel is increased in order to embed the touch panel function. In addition, a display drive integrated circuit (DDI) and a touch panel drive IC have to be separately arranged resulting in compatibility issues between the products. Also, it is difficult to attach the touch panel drive IC to a flexible printed circuit board (PCB).

SUMMARY OF THE INVENTION

An aspect of an embodiment of the present invention is directed towards an organic light emitting display device. In one embodiment, the display device includes an encapsulation substrate, an inner surface of which is patterned using indium tin oxide (ITO) pattern so that a touch panel function can be provided without increasing the thickness of the display device.

In one embodiment, an organic light emitting display device includes a substrate, a display unit on the substrate, an encapsulation substrate having a side facing the substrate, a touch unit facing the display unit and including a plurality of first sensors electrically coupled with each other and extending in parallel rows along a first direction, and a plurality of second sensors electrically coupled with each other and extending in parallel columns along a second direction crossing the first direction, and an insulation layer on at least a portion of the first sensors and second sensors.

In a further embodiment, the plurality of first sensors and the plurality of second sensors are on the side of the encapsulation substrate.

In a another embodiment, the plurality of first sensors and the plurality of second sensors are alternately arranged.

In a yet another embodiment, a projection of the plurality of first sensors in a plane parallel to the substrate is offset from a projection of the plurality of second sensors in the plane.

In a further embodiment, the organic light emitting display device further includes a flexible printed circuit board electrically coupled to the plurality of first sensors and to the plurality of second sensors.

In another embodiment, the organic light emitting display device further includes a data line at a periphery of the display unit on the substrate, the data line for delivering electrical signals generated by the touch unit to the flexible printed circuit board, and wherein the data line is electrically coupled to the plurality of first sensors and to the plurality of second sensors.

In still another embodiment, the organic light emitting display device further includes an electrical conductor between the data line and at least one of the first sensors and at least one of the second sensors, the electrical conductor for providing a conductive path between the data line and the at least one of the first sensors and the at least one of the second sensors.

In one embodiment, the organic light emitting display device further includes contact units at a periphery of an area including the plurality of first sensors and the second sensors, and an electrical conductor between the data line and the contact units to electrically couple the data line with the contact units.

In a further embodiment, the flexible printed circuit board includes circuitry for driving and controlling the display unit and for driving and controlling the touch unit.

In another embodiment, a display drive integrated circuit includes a touch unit drive integrated circuit.

In yet another embodiment, the display unit includes a thin film transistor on the substrate, and an organic light emitting diode coupled to the thin film transistor, the organic light emitting diode including a counter electrode, a pixel electrode, and an intermediate layer between the counter electrode and the pixel electrode.

In a further embodiment, the pixel electrode is in contact with the thin film transistor, wherein the intermediate layer is in contact with at least a portion of the pixel electrode, and wherein the counter electrode is in contact with at least a portion of the intermediate layer.

In one embodiment, the plurality of first sensors and the plurality of second sensors include indium tin oxide.

In a further embodiment, the touch panel is within a space between the substrate and the encapsulation substrate.

In an additional embodiment, the plurality of first sensors and the plurality of second sensors are configured to generate electrical signals indicative of a touch.

In one embodiment, each of the plurality of first sensors includes a first diamond shaped pad, and wherein each of the plurality of second sensors includes a second diamond shaped pad in a position adjacent to one of the first diamond shaped pads.

In a further embodiment, the first direction is perpendicular to the second direction.

In another embodiment, the touch unit is an electrostatic capacitive type touch unit.

In one embodiment, the organic light emitting display device further includes a first pattern layer on the side of the encapsulation substrate including the plurality of first sensors, and the plurality of second sensors, a second pattern layer on at least a portion of the insulation layer, the second pattern layer including a plurality of pattern units, each pattern unit configured to couple two of the plurality of second sensor on the first pattern layer.

In a further embodiment, the organic light emitting display device further includes a second insulation layer on at least a portion of the second pattern layer.

In one embodiment, the insulation layer includes a plurality of contact holes through which the pattern units are electrically coupled to the plurality of second sensors.

In another embodiment, each of the plurality of first sensors includes a first diamond shaped pad, wherein each of the plurality of second sensors includes a second diamond shaped pad in a position adjacent to one of the first diamond shaped pads, and wherein the plurality of contact holes are disposed at positions corresponding to corners of the second diamond shaped pads of the plurality of second sensors, where adjacent second sensors are coupled each other.

In a further embodiment, the pattern units are configured to fill the plurality of contact holes to electrically connect the second sensors that are adjacent to each other on the first pattern layer.

In one embodiment, the display unit includes a thin film transistor on the substrate, and an organic light emitting diode coupled to the thin film transistor, the organic light emitting diode including a counter electrode, a pixel electrode, and an intermediate layer between the counter electrode and the pixel electrode, and wherein the counter electrode and the first pattern layer are configured to form a first capacitor.

In another embodiment, the first pattern layer is further configured to form a second capacitor with an object approaching the encapsulation substrate, and wherein the first capacitor is electrically coupled in series with the second capacitor.

In still another embodiment, the organic light emitting display device further includes a flexible printed circuit board coupled to the plurality of first sensors and to the plurality of second sensors, and wherein the flexible printed circuit board includes circuitry for driving and controlling the touch unit.

In a further embodiment, the organic light emitting display further includes a data line at a periphery of the display unit on the substrate, the data line for delivering electrical signals generated by the touch unit to the flexible printed circuit board, and an electrical conductor between the substrate and the encapsulation substrate and for providing a conductive path between the touch unit on the encapsulation substrate to the data line.

In one embodiment, the flexible printed circuit board further includes a first PCB connecting unit and a second PCB connecting unit, and wherein the first PCB connecting unit links the display unit to the flexible printed circuit board and the second PCB connecting unit links the data line to the flexible printed circuit board.

In another embodiment, the organic light emitting display further includes a first pattern layer on the side of the encapsulation substrate, the first pattern layer including the plurality of first sensors, the insulation layer on at least a portion of the first pattern layer, a second pattern layer on at least a portion of the insulation layer, the second pattern layer including the plurality of second sensors, and a second insulation layer on at least a portion of the second pattern layer.

In a further embodiment, each of the plurality of first sensors includes a first diamond shaped pad, and wherein each of the plurality of second sensors includes a second diamond shaped pad in a position adjacent to one of the first diamond shaped pads.

In yet another embodiment, a plurality of first connecting units are configured to electrically connect the first sensors that are adjacent to each other on the first pattern layer, and wherein a plurality of second connecting units are configured to electrically connect the second sensors that are adjacent to each other on the second pattern layer.

In some embodiments, the display unit includes a thin film transistor on the substrate, and an organic light emitting diode coupled to the thin film transistor, the organic light emitting diode including a counter electrode, a pixel electrode, and an intermediate layer between the counter electrode and the pixel electrode, and wherein the counter electrode and the first pattern layer are configured to form a first capacitor.

In one embodiment, the first pattern layer is further configured to form a second capacitor with an object approaching the encapsulation substrate, and wherein the first capacitor is electrically coupled in series with the second capacitor.

In a further embodiment, the organic light emitting display device further includes a flexible printed circuit board coupled to the plurality of first sensors and to the plurality of second sensors, and wherein the flexible printed circuit board includes circuitry for driving and controlling the touch unit.

In another embodiment, the organic light emitting display further includes a data line at a periphery of the display unit on the substrate, the data line for delivering electrical signals generated by the touch unit to the flexible printed circuit board, and an electrical conductor between the substrate and the encapsulation substrate and for providing a conductive path between the touch unit on the encapsulation substrate to the data line.

In one embodiment, the flexible printed circuit board further includes a first PCB connecting unit and a second PCB connecting unit, wherein the first PCB connecting unit links the display unit to the flexible printed circuit board and the second PCB connecting unit links the data line to the flexible printed circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, together with the specification, illustrate exemplary embodiments of the present invention, and, together with the description, serve to explain the principles of the present invention.

FIG. 1 is a cross-sectional schematic view of a portion of an organic light emitting display device according to one embodiment of the present invention;

FIG. 2 is a plan schematic view of the organic light emitting display device of FIG. 1;

FIGS. 3A and 3B are bottom schematic views of an encapsulation substrate and a first pattern layer formed on a surface of the encapsulation substrate in the organic light emitting display device of FIG. 1;

FIG. 3C is a bottom schematic view of the first pattern layer of FIGS. 3A and 3B, and a second pattern layer on the first pattern layer;

FIG. 3D is a cross-sectional view taken along line III-III in FIG. 3C;

FIG. 3E is a bottom perspective schematic view of the first pattern layer and the second pattern layer of FIG. 3C;

FIG. 4 is a detailed plan schematic view of the organic light emitting display device of FIG. 1;

FIG. 5 is a cross-sectional view of the organic light emitting display device of FIG. 4;

FIG. 6 is a cross-sectional schematic view of a portion of the organic light emitting display device of FIG. 1;

FIG. 7A is a bottom schematic view of an encapsulation substrate and a first pattern layer formed on a surface of the encapsulation substrate in an organic light emitting display device according to one embodiment of the present invention;

FIG. 7B is a bottom schematic view of the first pattern layer of FIG. 7A, and a second pattern layer on the first pattern layer;

FIG. 7C is a cross-sectional schematic view taken along line VII-VII in FIG. 7B; and

FIG. 7D is a bottom perspective schematic view of the first pattern layer and the second pattern layer of FIG. 7B.

DETAILED DESCRIPTION

In the following detailed description, only certain exemplary embodiments of the present invention are shown and described, by way of illustration. As those skilled in the art would recognize, the invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Also, in the context of the present application, when an element is referred to as being “on” another element, it can be directly on the another element or be indirectly on the another element with one or more intervening elements interposed there between. Like reference numerals designate like elements throughout the specification.

FIG. 1 is a cross-sectional schematic view of a portion of an organic light emitting display device according to one embodiment of the present invention, and FIG. 2 is a plan schematic view of the organic light emitting display device of FIG. 1. In FIG. 2, the encapsulation substrate 300 illustrated in FIG. 1 is not shown.

Referring to FIGS. 1 and 2, a display unit 200 including a plurality of organic light emitting diodes (OLEDs) is formed on a substrate 100.

The substrate 100 may be formed of transparent glass containing SiO2 as a main component, but is not limited thereto, and thus may also be formed of a transparent plastic material that may be an insulating organic material selected from the group consisting of polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethyelene napthalate (PEN), polyethyelene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), triacetate cellulose (TAC), cellulose acetate propionate (CAP), and combinations thereof.

In one embodiment, if the organic light emitting display device of FIGS. 1 and 2 is a bottom emission type organic light emitting display device in which an image is realized toward the substrate 100, the substrate 100 is formed of a transparent material. However, in another embodiment, if the organic light emitting display device of FIGS. 1 and 2 is a top emission type organic light-emitting display device in which an image is realized away from the substrate 100, the substrate 100 may not be necessarily formed of a transparent material, and, in this case, the substrate 100 may be formed of a metal. When the substrate 100 is formed of a metal, the substrate 100 may include at least one material selected from the group consisting of carbon, iron, chromium, manganese, nickel, titanium, molybdenum, stainless steel (SUS), Invar alloys, Inconel alloys, and Kovar alloys, but is not limited thereto. In addition, the substrate 100 may also be formed of a metal foil.

Moreover, a buffer layer may be further formed on a top surface of the substrate 100 to planarize the substrate 100 and prevent or reduce impurities from penetrating into the bottom emission type organic light emitting display device.

The substrate 100, which includes a display unit 200 formed thereon, is attached to the encapsulation substrate 300 that is disposed above the display unit 200. The encapsulation substrate 300 may be formed of not only a glass material but also of various suitable plastic materials such as acryl, and furthermore, a metal. The encapsulation substrate 300 and touch panel related members formed on a surface of the encapsulation substrate 300 will be described later in more detail with reference to subsequent FIGS. 3A-3E.

Also, the substrate 100 and the encapsulation substrate 300 are attached to each other by using a sealant 250. The sealant 250 may be any suitable sealing glass frit. Also, the sealant 250 may be formed of an organic sealant, an inorganic sealant, or of a mixture of the organic and inorganic sealants.

Hereinafter, the encapsulation substrate 300, and the touch panel related members formed on the surface of the encapsulation substrate 300 in the organic light emitting display device according to an embodiment of the present invention will now be described in more detail.

FIGS. 3A and 3B are bottom schematic views of the encapsulation substrate 300 and a first pattern layer formed on a surface of the encapsulation substrate 300 in the organic light emitting display device of FIG. 1. FIG. 3C is a bottom schematic view of the first pattern layer of FIGS. 3A and 3B, and a second pattern layer on the first pattern layer. FIG. 3D is a cross-sectional view taken along line III-III in FIG. 3C. FIG. 3E is a bottom perspective schematic view of the first pattern layer and the second pattern layer of FIG. 3C.

Referring to FIGS. 3A through 3E, a first pattern layer 310, a first insulating layer 330, a second pattern layer 320, and a second insulating layer 340 (see FIG. 5) are sequentially formed on a surface of the encapsulation substrate 300, respectively, to face the substrate 100.

An issue with a conventional organic light emitting display device having an internal electrostatic capacitive type touch panel is that the thickness of the display device is increased in order to realize a touch panel function. In order to address this issue, an indium tin oxide (ITO) pattern is formed on an inner surface of the encapsulation substrate 300 of the organic light emitting display device according to one embodiment of the present invention.

To be more specific, the first pattern layer 310 is formed on the surface of the encapsulation substrate 300 to face the substrate 100 (see FIG. 1). The first pattern layer 310 includes a plurality of first direction pattern units 311 formed in parallel rows along a first direction (the X direction in FIG. 3A), and a plurality of second direction pattern units 312 formed in parallel columns along a second direction (the Y direction in FIG. 3B) that crosses (or is substantially perpendicular to) the first direction. As illustrated in FIGS. 3A and 3B, the first direction pattern units 311 and the second direction pattern units 312 are alternately disposed. That is, the first direction pattern units 311, each having a square shaped body rotated 45 degrees like a baseball diamond, are formed in parallel rows where horizontally opposite corners of each diamond are adjacent and coupled along the first direction (the X direction in FIG. 3A) on the surface of the encapsulation substrate 300. Similarly, the second direction pattern units 312, each having a square shaped body rotated 45 degrees like a baseball diamond, are formed in parallel columns where vertically opposite corners of each diamond are adjacent and coupled along the second direction (the Y direction in FIG. 3B) between each of the first direction pattern units 311. Here, in a number of embodiments, the pattern units (311 and 312) are utilized as sensors (or sensor pads).

Reference character A refers to one row of first direction pattern units 311 of FIG. 3A, where each row of first direction pattern units 311 includes a plurality of main bodies 311 a, a plurality of connecting units 311 b, an extending unit 311 c, and a contact unit 311 d. The main bodies 311 a have a diamond shape, and are formed in a row along the first direction, i.e., the X direction in FIG. 3A. The connecting units 311 b are formed between each of the main bodies 311 a, and respectively connect the main bodies 311 a that are adjacent to each other. The extending unit 311 c extends from an end of each of the first direction pattern units 311. The extending unit 311 c may be formed to extend in a direction, e.g., the Y direction in FIG. 3A, so that the plurality of extending units 311 c may be arranged at one end (or end portion) of the encapsulation substrate 300, that is, an upper end of the encapsulation substrate 300 in FIG. 3A. The contact unit 311 d is formed at an end (or upper end portion) of the extending unit 311 c, and is electrically connected to a substrate contact unit 112 of a data line 110 (see FIG. 5) on the substrate 100 (see FIG. 5) via a conductive member 120 (see FIG. 5).

In FIG. 3B, reference character B refers to one column of second direction pattern units 312. Each column of second direction pattern units 312 includes a plurality of main bodies 312 a, an extending unit 312 c, and a contact unit 312 d. The main bodies 312 a have a diamond shape, and are formed in a column along the second direction, i.e., the Y direction in FIG. 3B. Unlike the first direction pattern units 311, none of the second direction pattern units 312 includes a connecting unit. The main bodies 312 a are connected to each other not by a connecting unit but by the second pattern layer 320 having, e.g., a plurality of third pattern units 325 for connecting the main bodies 312 a to each other (see FIG. 3E). The extending unit 312 c extends from a contact unit 312 d to a point in close proximity to a corner of a diamond shaped main body 312 a closest to an upper end of the encapsulation substrate 300. The extending unit 312 c may be formed to extend in a direction, e.g., the Y direction in FIG. 3B, so that a plurality of extending units 312 c may be arranged at one end of the encapsulation substrate 300, that is, an upper end of the encapsulation substrate 300 in FIG. 3B. The contact unit 312 d is formed at an end of the extending unit 312 c, and is electrically connected to a substrate contact unit of the data line 110 (see FIG. 5) on the substrate 100 (see FIG. 5) via the conductive member 120 (see FIG. 5).

Referring to FIGS. 3D and 3E, the first insulating layer 330 is formed on the surface of the encapsulation substrate 300 such that it faces the substrate 100 (see FIG. 1) and covers the first pattern layer 310. The first insulating layer 330 insulates the first pattern layer 310 from the second pattern layer 320. A plurality of contact holes (or vias) 331 may be formed at predetermined positions in the first insulating layer 330, e.g., at positions that correspond to adjacent corners of the diamond shaped main bodies 312 a of the second direction pattern units 312. The second pattern layer 320 and the main bodies 312 a of the second direction pattern units 312 are electrically connected via the contact holes 331.

As illustrated in FIGS. 3C through 3E, the second pattern layer 320 is formed on a surface of the first insulating layer 330 to face the substrate 100 (see FIG.1). The second pattern layer 320, a conductive layer, is formed such that it fills the contact holes 331 of the first insulating layer 330, thereby electrically connecting (e.g. by vias and third pattern units 325) the main bodies 312 a of second direction pattern units 312, that are adjacent to each other.

In this manner, the first direction pattern units 311 and the second direction pattern units 312, which are alternately disposed, do not intersect (or electrically couple) each other, so that a short circuit between the first direction pattern units 311 and the second direction pattern units 312 is prevented.

The first pattern layer 310 and the second pattern layer 320 may be formed of suitable transparent materials such as ITO, IZO, ZnO, and/or In2O3. Also, the first pattern layer 310 and the second pattern layer 320 may be formed by using a photolithography process. That is, an ITO layer formed by using a suitable deposition method, a spin coating method, a sputtering method, or an inkjet method may be used to form the first pattern layer 310 and the second pattern layer 320.

Referring now to FIG. 5, a second insulating layer 340 is formed both on the surface of the first insulating layer 330 to face the substrate 100 and on the surface of the second pattern layer 320. An opposite side of the second insulating layer 340 abuts the display unit 200. The second insulating layer 340 insulates the second pattern layer 320 from a display unit 200.

In this manner, according to one embodiment of the present invention, it is possible to realize a touch panel function without increasing the thickness of a display device. Also, because an electrostatic capacitive pattern is formed on the inner surface of the encapsulation substrate 300, slim (or thin) etching is possible.

Hereinafter, the connection relationship between a pattern layer of an encapsulation substrate, and a printed circuit board (PCB) of a substrate will now be described in more detail.

FIG. 4 is a detailed plan schematic view of the organic light emitting display device of FIG. 1, and FIG. 5 is a cross-sectional view of the organic light emitting display device of FIG. 4.

Referring to FIGS. 4 and 5, a contact unit 311 d of a first direction pattern unit 311, and a contact unit 312 d of a second direction pattern unit 312, which are formed on an encapsulation substrate 300, are electrically connected to a data line 110 formed on the substrate 100. To make this connection, the organic light emitting display device according to one embodiment of the present invention includes a conductive member 120.

To be more specific, a display unit 200 for displaying an image is formed above the substrate 100 (the display unit 200 will be described later in more detail with reference to FIG. 6). A flexible PCB 130, on which various suitable electrical components for driving and controlling the display unit 200 are disposed, is arranged with the display unit 200. A display drive integrated circuit (DDI) 111 is arranged between the display unit 200 and the flexible PCB 130 to drive the display unit 200. The DDI 111 and the flexible PCB 130 may be connected by a plurality of input/output lines 115.

The data line 110 is formed around the display unit 200 and above the substrate 100. The data line 110 is used to deliver electrical signals, which are generated by the first and second pattern layers (310 and 320) formed on the inner surface of the encapsulation substrate 300, to the flexible PCB 130. For delivery of these electrical signals, the data line 110 further includes a plurality of substrate contact units 112 located on the substrate (see FIG. 5).

The substrate contact units 112 are formed on the substrate at positions corresponding to positions of the contact units 311 d of the first direction pattern units 311, and corresponding to positions of the contact units 312 d of the second direction pattern unit 312. The substrate contact units 112 are formed on the substrate 100, and the contact units 311 d and 312 d are formed on the encapsulation substrate 300 and both are electrically connected by the conductive member 120. Various conductive materials including a silver paste may be used for the conductive member 120. The substrate contact units 112 are individually connected to data line 110 which is connected to the flexible PCB 130.

A touch panel drive IC (TDI) 113 configured to receive the electrical signals to drive and control the touch panel is disposed on the flexible PCB 130, where the electrical signals are generated by the first and second pattern layers 310 and 320 formed on the inner surface of the encapsulation substrate 300.

In this manner, the organic light emitting display device according to one embodiment of the present invention includes a conventional flexible PCB used in a display device to provide an integrated interface for enabling a touch panel function. By doing so, it is possible to effectively reduce manufacturing costs, and to improve the ease of manufacture and the user's convenience.

Also, referring to FIG. 4, the DDI 111 and the TDI 113 are shown to be separately arranged but the present invention is not limited thereto. That is, although not illustrated in the drawing, the DD1 111 may be implemented to include the functions of the TDI 113 in some embodiments. In this case, the data line 110 may be configured to be directly connected to the DD1 111. By doing so, it is possible to effectively further reduce the manufacturing costs, and to improve the manufacture and user's convenience.

Hereinafter, a structure of a display unit in the organic light emitting display device according to one embodiment of the present invention will now be described in detail.

FIG. 6 is a cross-sectional view of a portion of the organic light emitting display device of FIG. 1, showing a detailed configuration of the display unit 200.

Referring to FIG. 6, a plurality of thin film transistors 220 are formed on the substrate 100, and an organic light emitting diode (OLED) 230 is formed on (or with) each of the thin film transistors 220. The OLED 230 includes a pixel electrode 231 electrically connected to the thin film transistor 220, a counter electrode 235 disposed entirely on the substrate 100, and an intermediate layer 233 disposed between the pixel electrode 231 and the counter electrode 235 that includes a light emitting layer.

The thin film transistors 220, each of which includes a gate electrode 221, source and drain electrodes 223, a semiconductor layer 227, a gate insulating layer 213, and an interlayer insulating layer 215, are formed on the substrate 100. The current embodiment is not limited to the thin film transistors 220 of FIG. 3D. Thus other thin film transistors such as an organic thin film transistor including a semiconductor layer formed of an organic material or a silicon thin film transistor formed of silicon may also be used. In some embodiments, a buffer layer 211 formed of a silicon oxide or a silicon nitride may be further included between the thin film transistors 220 and the substrate 100.

The OLED 230 includes the pixel electrode 231 and the counter electrode 235 which effectively face each other. The OLED further includes the intermediate layer 233 formed of an organic material and disposed between the pixel electrode 231 and the counter electrode 235. The intermediate layer 233, which includes the light emitting layer, may also include a plurality of layers.

The pixel electrode 231 functions as an anode electrode, and the counter 235 functions as a cathode electrode. However, the polarity of the pixel electrode 231 and the counter electrode 235 may be switched.

The pixel electrode 231 may be formed as a transparent electrode or a reflective electrode. When formed as a transparent electrode, the pixel electrode 231 may be formed of ITO, IZO, ZnO, and/or In2O3. When formed as a reflective electrode, the pixel electrode 231 may include a reflection layer formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr or combinations thereof, and a layer including ITO, IZO, ZnO, and/or In2O3, formed on the reflection layer.

The counter electrode 235 may also be formed as a transparent electrode or a reflective electrode. When formed as a transparent electrode, the counter electrode 235 may include a layer in which Li, Ca, LiF/Ca, LiF/Al, Al, Mg, or combinations thereof, is deposited on the intermediate layer 233 between the pixel electrode 231 and the counter electrode 235. In some embodiments, the counter electrode layer may also include a bus electrode line and an auxiliary electrode formed of ITO, IZO, ZnO, and/or In2O3. When formed as a reflective electrode, the counter electrode 235 may be formed by depositing Li, Ca, LiF/Ca, LiF/Al, Al, Mg or combinations thereof.

A pixel defining layer (PDL) 219 is formed to cover an edge (or edge portion) of the pixel electrode 231 and to have a thickness (or a predetermined thickness) measured from the pixel electrode 231 to the counter electrode 235. The PDL 219 defines a light emitting region, and provides a wide gap between the edge of the pixel electrode 231 and the counter electrode 235 to prevent an electric field from being concentrated on the edge of the pixel electrode 231, and thereby preventing (or protecting from) a potential short circuit between the pixel electrode 231 and the counter electrode 235.

A plurality of intermediate layers 233 each including at least a light emitting layer, may be formed between each respective pixel electrode 231 and each respective counter electrode 235. In FIG. 6, the intermediate layer 233 may be formed of a low molecule organic material or a polymer organic material.

When formed of a low molecule organic material, the intermediate layer 233 may have a single-layer or multiple-layer structure in which a hole injection layer (HIL), a hole transport layer (HTL), an organic light emission layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) are stacked. Examples of the organic material include copper phthalocyanine (CuPc), N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), tris-8-hydroxyquinoline aluminum (Alq3), etc. The low molecule organic material may be formed using a vacuum deposition method and a mask.

When formed of a polymer organic material, the intermediate layer 233 may have a structure formed of an HTL and an EML; the HTL may be formed of poly(3,4-ethylenedioxythiophene) (PEDOT), and the EML may be formed of poly-phenylenevinylene (PPV) and polyfluorene.

The OLED 230 is electrically connected to the thin film transistor 220 disposed there below. When a planarization layer 217 covering the thin film transistor 220 is formed, the OLED 230 is disposed on top of the planarization layer 217, and the pixel electrode 231 is electrically connected to the thin film transistor 220 via contact holes formed in the planarization layer 217.

In the embodiment illustrated in FIG. 6, the OLED 230 formed on the substrate 100 is sealed by the encapsulation substrate 300. The encapsulation substrate 300 may be formed of various suitable materials such as glass or plastic, as described above. Also, as described above, pattern layers (refer to as the first pattern layer 310 and the second pattern layer 320 in FIG. 5), and insulating layers (refer to as the first insulating layer 330 and the second insulating layer 340 in FIG. 5) are sequentially formed on the inner surface of the encapsulation substrate 300, thereby making it possible to provide a touch panel function.

A method of driving the organic light emitting display device according to one embodiment of the present invention will now be briefly described.

Referring back to FIGS. 4 and 5, when a finger, a conductive object, or a high dielectric object approaches or touches a surface of the organic light emitting display device according to one embodiment of the present invention, the organic light emitting display device interprets a change of an electrostatic charge (capacitance) of conductors caused by such approach, thereby sensing a touch. Based on the touch, an output is generated that includes the coordinates of the touch on the surface, and the pressing value.

To be more specific, as a constant voltage, a cathode voltage flows in the counter electrode 235 (see FIG. 6) of the display unit 200 which contacts the second insulating layer 340. Thus, the first pattern layer 310 and the counter electrode 235 form one capacitor, and an electrostatic charge between the first pattern layer 310 and the counter electrode 235 is maintained constant. If a finger, a conductive object, or a high dielectric object approaches or touches a surface above the encapsulation substrate 300, the finger and the first pattern layer 310 form a second capacitor. These two capacitors are effectively connected in serial, and an entire electrostatic charge changes with a touch. By using the position where the change of the electrostatic charge occurs, and a magnitude of the change, a touch sensing system can sense a touch, including the magnitude, and locate the position of the touch.

FIG. 7A is a bottom schematic view of an encapsulation substrate 400 and a first pattern layer 410 formed on a surface of the encapsulation substrate 400 in an organic light emitting display device according to another embodiment of the present invention. FIG. 7B is a bottom schematic view of the first pattern layer 410 of FIG. 7A, and a second pattern layer 420 on top of the first pattern layer. FIG. 7C is a cross-sectional view taken along line VII-VII in FIG. 7B. FIG. 7D is a bottom perspective schematic view of the first pattern layer 410 and the second pattern layer 420 of FIG. 7B.

Referring to FIGS. 7A through 7D, the first pattern layer 410, a first insulating layer 430, the second pattern layer 420, and a second insulating layer 440 are sequentially formed on a surface of the encapsulation substrate 400, respectively, to face a substrate.

In the embodiment illustrated in FIGS. 7A through 7D, the first and second direction pattern units are not formed using a single pattern layer. Instead, the first direction pattern units 411 are formed using the first pattern layer 410, while the second direction pattern units 421 are formed using the second pattern layer 420.

To be more specific, the first pattern layer 410 is formed on the surface of the encapsulation substrate 400 to face the substrate 100 (see FIG. 1). The first pattern layer 410 includes a plurality of first direction pattern units 411 formed in parallel rows along a first direction (the X direction in FIG. 7A). Reference character A illustrated in FIG. 7A refers to one row of first direction pattern units 411. As illustrated in FIG. 7A, the first direction pattern units 411 are formed in parallel rows. Here, in a number of embodiments, the pattern units (411 and 421) are used as sensors (or sensor pads).

Reference character A in FIG. 7A, refers to one row of first direction pattern units 411, where each row of first direction pattern units 411 includes a plurality of main bodies 411 a, a plurality of connecting units 411 b, an extending unit 411 c, and a contact unit 411 d. The main bodies 411 a have a diamond shape, and are formed in parallel rows along the first direction, i.e., the X direction in FIG. 7A. The connecting units 411 b are formed between each of the main bodies 411 a, thereby connecting the main bodies 411 a which are adjacent to each other. The extending unit 411 c extends from an end of each of the first direction pattern units 411. The extending unit 411 c may be formed to extend in a direction, e.g., a Y direction in FIG. 7A, so that a plurality of extending units 411 c may be arranged at one end of the encapsulation substrate 400, that is, an upper end of the encapsulation substrate 400 in FIG. 7A. The contact unit 411 d is formed at an end of the extending unit 411 c, and is electrically connected to a substrate contact unit of the data line of the substrate via a conductive member.

Referring to FIGS. 7C and 7D, the first insulating layer 430 is formed on the surface of the encapsulation substrate 400 to face the substrate and to cover the first pattern layer 410. The first insulating layer 430 insulates the first pattern layer 410 from the second pattern layer 420.

As illustrated in FIGS. 7B through 7D, the second pattern layer 420 is formed on top of the first insulating layer 430 to face the substrate 100 (see FIG. 1).

To be more specific, the second pattern layer 420 includes the second direction pattern units 421 formed in parallel columns along a second direction (the Y direction in FIG. 7B). Reference character B illustrated in FIG. 7B indicates one column of second direction pattern units 421. As illustrated in FIG. 7B, the second direction pattern units 421 are formed in parallel columns. In FIG. 7B, dashed or hidden lines indicate the first pattern layer 410 illustrated in FIG. 7A.

In FIG. 7B, reference character B refers to one column of second direction pattern units 421. Each column of second direction pattern units 421 includes a plurality of main bodies 421 a, an extending unit 421 c, and a contact unit 421 d. The main bodies 421 a have a diamond shape, and are formed in a column along the second direction, i.e., the Y direction in FIG. 7B. The connecting units 421 b are formed between each of the main bodies 421 a, thereby connecting the main bodies 421 a which are adjacent to each other. The extending unit 421 c extends from an end of each of the second direction pattern units 421. The extending unit 421 c may be formed to extend in a direction, e.g., the Y direction in FIG. 7B, so that a plurality of extending units 421 c may be arranged at one end of the encapsulation substrate 400, that is, an upper end of the encapsulation substrate 400 in FIG. 7B. The contact unit 421 d is formed at an end of the extending unit 421 c, and is electrically connected to a substrate of the data line of the substrate via the conductive member.

The first pattern layer 410 and the second pattern layer 420 may be formed of transparent materials such as ITO, IZO, ZnO, or In2O3. Also, the first pattern layer 410 and the second pattern layer 420 may be formed by using a photolithography process. That is, an ITO layer formed by using a deposition method, a spin coating method, a sputtering method, and/or an inkjet method may be used to form the first pattern layer 410 and the second pattern layer 420.

Referring now to FIG. 7C, a second insulating layer 440 is formed on both the first insulating layer 430 to face the substrate and on the second pattern layer 420. An opposite side of the second insulating layer 440 faces (e.g., abuts) the display unit. The second insulating layer 440 insulates the second pattern layer 420 from a display unit 200 (see FIG. 5).

In this manner, according to the embodiments of the present invention, it is possible to provide a display panel with a touch panel function without increasing the thickness of the display panel. Also, because an electrostatic capacitive pattern is formed on an inner surface of the encapsulation substrate, slim (or thin) etching is possible.

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, and equivalents thereof. 

What is claimed is:
 1. An organic light emitting display device comprising: a substrate; a display unit directly formed on the substrate; an encapsulation substrate having a side facing the substrate, wherein the display unit is positioned between the encapsulation substrate and the substrate; a touch unit between the display unit and the encapsulation substrate, the touch unit comprising: a plurality of first sensors electrically coupled with each other and extending in parallel rows along a first direction, and a plurality of second sensors electrically coupled with each other and extending in parallel columns along a second direction crossing the first direction; and an insulation layer on at least a portion of the first sensors and second sensors, the insulation layer being directly on a surface of the display unit, the touch unit being directly on a surface of the insulation layer, and the encapsulation substrate being directly on a surface of the touch unit.
 2. The organic light emitting display device of claim 1, wherein the plurality of first sensors and the plurality of second sensors are directly on the surface of the encapsulation substrate.
 3. The organic light emitting display device of claim 1, wherein the plurality of first sensors and the plurality of second sensors are alternately arranged.
 4. The organic light emitting display device of claim 1, wherein a projection of the plurality of first sensors in a plane parallel to the substrate is offset from a projection of the plurality of second sensors in the plane.
 5. The organic light emitting display device of claim 1, further comprising a flexible printed circuit board electrically coupled to the plurality of first sensors and to the plurality of second sensors.
 6. The organic light emitting display device of claim 5, further comprising a data line at a periphery of the display unit on the substrate, the data line for delivering electrical signals generated by the touch unit to the flexible printed circuit board; and wherein the data line is electrically coupled to the plurality of first sensors and to the plurality of second sensors.
 7. The organic light emitting display device of claim 6, further comprising an electrical conductor between the data line and at least one of the first sensors and at least one of the second sensors, the electrical conductor for providing a conductive path between the data line and the at least one of the first sensors and the at least one of the second sensors.
 8. The organic light emitting display device of claim 6, further comprising contact units at a periphery of an area comprising the plurality of first sensors and the second sensors; and an electrical conductor between the data line and the contact units to electrically couple the data line with the contact units.
 9. The organic light emitting display device of claim 5, wherein the flexible printed circuit board comprises circuitry for driving and controlling the display unit and for driving and controlling the touch unit.
 10. The organic light emitting display device of claim 5, wherein a display drive integrated circuit comprises a touch unit drive integrated circuit.
 11. The organic light emitting display device of claim 1, wherein the display unit comprises: a thin film transistor on the substrate; and an organic light emitting diode coupled to the thin film transistor, the organic light emitting diode comprising a counter electrode, a pixel electrode, and an intermediate layer between the counter electrode and the pixel electrode.
 12. The organic light emitting display device of claim 11, wherein the pixel electrode is in contact with the thin film transistor, wherein the intermediate layer is in contact with at least a portion of the pixel electrode, and wherein the counter electrode is in contact with at least a portion of the intermediate layer.
 13. The organic light emitting display device of claim 1, wherein the plurality of first sensors and the plurality of second sensors comprise indium tin oxide.
 14. The organic light emitting display device of claim 1, wherein the touch unit fills a space between the display unit-and the encapsulation substrate.
 15. The organic light emitting display device of claim 1, wherein the plurality of first sensors and the plurality of second sensors are configured to generate electrical signals indicative of a touch.
 16. The organic light emitting display device of claim 1: wherein each of the plurality of first sensors comprises a first diamond shaped pad; and wherein each of the plurality of second sensors comprises a second diamond shaped pad in a position adjacent to one of the first diamond shaped pads.
 17. The organic light emitting display device of claim 1, wherein the first direction is perpendicular to the second direction.
 18. The organic light emitting display device of claim 1, wherein the touch unit is an electrostatic capacitive type touch unit.
 19. The organic light emitting display device of claim 1, further comprising: a first pattern layer on the side of the encapsulation substrate comprising: the plurality of first sensors, and the plurality of second sensors; a second pattern layer on at least a portion of the insulation layer, the second pattern layer comprising a plurality of pattern units, each pattern unit configured to couple two of the plurality of second sensors on the first pattern layer.
 20. The organic light emitting display device of claim 19, further comprising a second insulation layer on at least a portion of the second pattern layer.
 21. The organic light emitting display device of claim 19, wherein the insulation layer comprises a plurality of contact holes through which the pattern units are electrically coupled to the plurality of second sensors.
 22. The organic light emitting display device of claim 21: wherein each of the plurality of first sensors comprises a first diamond shaped pad; wherein each of the plurality of second sensors comprises a second diamond shaped pad in a position adjacent to one of the first diamond shaped pads; and wherein the plurality of contact holes are disposed at positions corresponding to corners of the second diamond shaped pads of the plurality of second sensors, where adjacent second sensors are coupled to each other.
 23. The organic light emitting display device of claim 21, wherein the pattern units are configured to fill the plurality of contact holes to electrically connect the second sensors that are adjacent to each other on the first pattern layer.
 24. The organic light emitting display device of claim 19: wherein the display unit comprises: a thin film transistor on the substrate; and an organic light emitting diode coupled to the thin film transistor, the organic light emitting diode comprising a counter electrode, a pixel electrode, and an intermediate layer between the counter electrode and the pixel electrode; and wherein the counter electrode and the first pattern layer are configured to form a first capacitor.
 25. The organic light emitting display device of claim 24: wherein the first pattern layer is further configured to form a second capacitor with an object approaching the encapsulation substrate; and wherein the first capacitor is electrically coupled in series with the second capacitor.
 26. The organic light emitting display device of claim 19: further comprising a flexible printed circuit board coupled to the plurality of first sensors and to the plurality of second sensors; and wherein the flexible printed circuit board comprises circuitry for driving and controlling the touch unit.
 27. The organic light emitting display of claim 26, further comprising: a data line at a periphery of the display unit on the substrate, the data line for delivering electrical signals generated by the touch unit to the flexible printed circuit board; and an electrical conductor between the substrate and the encapsulation substrate and for providing a conductive path between the touch unit on the encapsulation substrate to the data line.
 28. The organic light emitting display of claim 27: wherein the flexible printed circuit board further comprises a first PCB connecting unit and a second PCB connecting unit; and wherein the first PCB connecting unit links the display unit to the flexible printed circuit board and the second PCB connecting unit links the data line to the flexible printed circuit board.
 29. The organic light emitting display of claim 1, further comprising: a first pattern layer on the side of the encapsulation substrate, the first pattern layer comprising the plurality of first sensors; the insulation layer on at least a portion of the first pattern layer; a second pattern layer on at least a portion of the insulation layer, the second pattern layer comprising the plurality of second sensors; and a second insulation layer on at least a portion of the second pattern layer.
 30. The organic light emitting display device of claim 29: wherein each of the plurality of first sensors comprises a first diamond shaped pad; and wherein each of the plurality of second sensors comprises a second diamond shaped pad in a position adjacent to one of the first diamond shaped pads.
 31. The organic light emitting display device of claim 29: wherein a plurality of first connecting units are configured to electrically connect the first sensors that are adjacent to each other on the first pattern layer; and wherein a plurality of second connecting units are configured to electrically connect the second sensors that are adjacent to each other on the second pattern layer.
 32. The organic light emitting display device of claim 29: wherein the display unit comprises: a thin film transistor on the substrate; and an organic light emitting diode coupled to the thin film transistor, the organic light emitting diode comprising a counter electrode, a pixel electrode, and an intermediate layer between the counter electrode and the pixel electrode; and wherein the counter electrode and the first pattern layer are configured to form a first capacitor.
 33. The organic light emitting display device of claim 32: wherein the first pattern layer is further configured to form a second capacitor with an object approaching the encapsulation substrate; and wherein the first capacitor is electrically coupled in series with the second capacitor.
 34. The organic light emitting display device of claim 29: further comprising a flexible printed circuit board coupled to the plurality of first sensors and to the plurality of second sensors; and wherein the flexible printed circuit board comprises circuitry for driving and controlling the touch unit.
 35. The organic light emitting display of claim 34, further comprising: a data line at a periphery of the display unit on the substrate, the data line for delivering electrical signals generated by the touch unit to the flexible printed circuit board; and an electrical conductor between the substrate and the encapsulation substrate and for providing a conductive path between the touch unit on the encapsulation substrate to the data line.
 36. The organic light emitting display of claim 35, wherein the flexible printed circuit board further comprises a first PCB connecting unit and a second PCB connecting unit, wherein the first PCB connecting unit links the display unit to the flexible printed circuit board and the second PCB connecting unit links the data line to the flexible printed circuit board. 